Adventures of a multidimensional freak

This is Juan Julián Merelo Guervós English-language blog. He teaches computer science at the University of Granada, in southern Spain. Come back here to read about politics, technology, with a new twist

I knew this blog on HP7 statistics would sooner or later turn up something interesting. In this case, between Wednesday and Thursday, around 1000 books have disappeared from the number of second hand books for sale. What's happened? Did somebody buy them all? Is somebody trying to create artificial scarcity of HP7 books? Were they abducted by Hogwarts High Librarian?